Typical connector systems include a cable assembly and a connector mounted on a board such as a printed circuit board (PCB). The cable assembly, which commonly includes a pair of plug connectors on opposite ends of a cable, is configured to transmit signals over a certain distance. The board-mounted connector may comprise a receptacle, or cage, configured to receive and mate with one of the plug connectors, ensuring a secure connection between the cable assembly and an interface on the board. A signal (such as an electrical or optical signal) may thus be received at the interface via the cable, or transmitted from the interface via the cable.
One issue that has arisen in the development of such connector systems is the build-up of heat in and around the receptacle. This problem is particularly pronounced for active cable assemblies (i.e. cables having embedded circuitry to boost their performance). In order to address this problem, heat sinks have been used to dissipate the heat that builds up in the connector.
FIG. 1 is a schematic diagram of a conventional interface module 100, shown in cross section. The interface module 100 may be suitable for use in a larger apparatus, such as a computer system, a server, or another network component, for inputting or outputting signals via an electrical or optical cable assembly.
The module 100 comprises a housing 102, which substantially encloses and surrounds the internal components of the module 100. A PCB 104 is fixed to one internal surface of the housing 102, and a cage or receptacle 106 is fixed to the PCB 104. The cage 106 is hollow, and comprises an opening, a rear face opposite the opening, and a main body extending between the opening and the rear face. The opening is aligned with a corresponding opening in the housing 102, such that a connector (e.g. a connector for a cable assembly) can be inserted through the opening, and is guided towards the rear of the cage by the main body. The cage 106 may define an internal space or bore, having a cross section that complements the cross section of the connector, so as to guide the connector accurately to an interface 108 that is positioned towards the rear of the cage 106. When the connector is fully inserted in the cage 106, it mates with the interface 108 such that signals can pass from the connector to the PCB 104 via the interface 108, or from the PCB 104 to the connector via the interface 108.
In order to dissipate excess heat that may build up in the connector while in use, the module 100 further comprises a heat sink 110 that extends over an upper surface of the cage 106. In the illustration the heat sink 110 is supported by the PCB 104, but alternatively the heat sink 110 may be coupled to an internal surface of the module 100 or some other structure within the module 100. The heat sink 110 may be manufactured from a material having a high thermal conductivity, and comprise one or more fins or other features designed to dissipate heat.
One factor that affects the efficiency of the heat sink is its thermal interface with the heat source, i.e. the connector. In order to improve the thermal interface between the heat sink and the connector, the cage 106 may comprise one or more apertures 112 through which the heat sink 110 can be coupled directly to the connector. For example, FIG. 1 shows a single, large aperture 112 in the upper surface of the cage 106. The heat sink 110 may comprise one or more corresponding features that extend through the aperture to engage with the connector once it is inserted into the cage 106. One or more spring clips may be used to hold and press the heat sink 110 and the cage 106 together, to increase the thermal contact between the heat sink 110 and the connector.
However, there are a number of problems with the arrangement shown in FIG. 1. One problem is the number of components required to achieve an adequate thermal connection between the connector and the heat sink. For example, spring clips may be required to press the heat sink 110 and the cage 106 together. Such clips may be difficult to handle, even in automated manufacturing systems. Further, the heat sink 110 itself is a large component that takes up a considerable volume within the interface module 100.
A connector system is required that addresses one or more of these problems.